He may be telling you he's "about to break up" because you're literally in heat and he's noticed, but I don't think a girl who's about to break up would be telling other girls about her man's big dick.... so I guess she's not informed that they're "about to break up".
You can probably have sex with him, until
a) his girlfriend forgives him and he'll be back with her
b) he decides to enjoy his newfound freedom by trying as many flavors as he can
You can probably have sex with him, until
a) his girlfriend forgives him and he'll be back with her
b) he decides to enjoy his newfound freedom by trying as many flavors as he can